So I've got a computer power supply and I've been thinking about modifying it a little bit to power my 2 meter radio for APRS. I know the thing supplies 12 volts but so do car batteries when the car is off. I'm only going to push 25 watts out of it anyway (It's a Kenwood TM-281a so my only options are 25 and 65 watts). I'm thinking that what I'll need to do is solder all the yellow cables together for a big +12 volt line, solder all the black cables together for ground, then solder all the red cables together for +5 volts to power my Raspberry Pi. I then plan on buying a volt and ammeter (maybe a combo device?) so I can make sure I'm getting proper voltage and checking on how many amps I'm drawing. Any suggestions? Should I not do this, do it, anything? Thanks!